{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-41263",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-04-18T14:01:46.801Z",
        "datePublished": "2026-04-30T20:39:49.658Z",
        "dateUpdated": "2026-05-01T14:22:40.566Z"
    },
    "containers": {
        "cna": {
            "title": "Traefik: BasicAuth middleware: timing side-channel vulnerability",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-208",
                            "lang": "en",
                            "description": "CWE-208: Observable Timing Discrepancy",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "HIGH",
                        "attackRequirements": "NONE",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "NONE",
                        "vulnIntegrityImpact": "NONE",
                        "vulnAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "LOW",
                        "subIntegrityImpact": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 6.3,
                        "baseSeverity": "MEDIUM",
                        "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N",
                        "version": "4.0"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/traefik/traefik/security/advisories/GHSA-6x2q-h3cr-8j2h",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/traefik/traefik/security/advisories/GHSA-6x2q-h3cr-8j2h"
                },
                {
                    "name": "https://github.com/traefik/traefik/releases/tag/v2.11.43",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/traefik/traefik/releases/tag/v2.11.43"
                },
                {
                    "name": "https://github.com/traefik/traefik/releases/tag/v3.6.14",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/traefik/traefik/releases/tag/v3.6.14"
                },
                {
                    "name": "https://github.com/traefik/traefik/releases/tag/v3.7.0-rc.2",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/traefik/traefik/releases/tag/v3.7.0-rc.2"
                }
            ],
            "affected": [
                {
                    "vendor": "traefik",
                    "product": "traefik",
                    "versions": [
                        {
                            "version": "< 2.11.43",
                            "status": "affected"
                        },
                        {
                            "version": ">= 3.0.0-beta1, < 3.6.14",
                            "status": "affected"
                        },
                        {
                            "version": ">= 3.7.0-ea.1, < 3.7.0-rc.2",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-04-30T20:39:49.658Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Traefik is an HTTP reverse proxy and load balancer. Prior to versions 2.11.43, 3.6.14, and 3.7.0-rc.2, there is a timing side-channel vulnerability in Traefik's BasicAuth middleware that allows an attacker to enumerate valid usernames through response-time differences. The variable intended to hold a constant-time fallback secret always resolves to an empty string, causing the constant-time comparison to short-circuit in microseconds rather than performing a full bcrypt evaluation. This restores the original timing oracle and makes it possible to distinguish existing users from non-existing ones by measuring authentication response times. This issue has been patched in versions 2.11.43, 3.6.14, and 3.7.0-rc.2."
                }
            ],
            "source": {
                "advisory": "GHSA-6x2q-h3cr-8j2h",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-05-01T14:22:30.689474Z",
                                "id": "CVE-2026-41263",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-05-01T14:22:40.566Z"
                }
            }
        ]
    }
}